Doctors label cancer by stages. Stages show how much cancer is in your body, how far it has spread and how quickly it may grow.   

Stages help doctors and patients understand how serious cancer is. Stages also help your Knight Cancer Institute team know how to best treat the cancer.

What is cancer staging?

With lung cancer, stages show:

• The size of the main tumor
• Whether it has spread to lymph nodes
• Whether it has spread to other areas of the body, like the bones or liver

Doctors determine lung cancer stages through:

• Physical exam
• Imaging tests, such as CT or PET scans
• Biopsies (removing small tissue samples and looking at them under a microscope)

Understanding lung cancer stages

The lower the stage number, the less the cancer has spread. For example:

• A stage 0 cancer is the earliest stage. Abnormal cells have not spread.
• A stage IV, or 4, is advanced lung cancer. It has spread to other parts of the body.

Here are the stages for non-small cell lung cancer, the much more common type of lung cancer.

Stage 0

Abnormal cells are in only the top lining of the lung or the bronchus (a tube that connects the windpipe and a lung).

Stage I

The cancer has not spread to lymph nodes or other parts of the body.

Stage IA: The tumor is 3 centimeters across or less.

Stage IB Lung Cancer

Stage IB: One or more of these:

• The tumor is between 3 and 4 centimeters.
• The tumor is 4 centimeters or less, and one of these:
  • Cancer has spread to an airway (bronchus).
  • Cancer has spread to the inner membrane that covers the lung.
  • Cancer partly clogs the airways.

Stage II

The cancer has spread within or around the lungs, or to nearby lymph nodes.

Stage IIA Lung Cancer

Stage IIA: The tumor is between 4 and 5 centimeters, and one of these:

• Cancer has spread to the bronchus, the airway connecting the lung and windpipe.
• Cancer has spread to the membrane around the lung.
• Cancer partly clogs the airways.

Stage IIB: One of these:

The tumor is 3 centimeters across or less. Cancer has spread to nearby lymph nodes.

The tumor is between 3 and 5 centimeters. Cancer has spread to nearby lymph nodes. Also one of these:

• Cancer has spread to the bronchus, the airway connecting the lung and windpipe.
• Cancer has spread to the membrane around the lung.
• Cancer partly clogs the airways.

The tumor is between 5 and 7 centimeters.

• One lung lobe has multiple tumors.
• Cancer has spread to any of these: the chest membrane, the chest wall, the nerve between the lung and heart, or tissue around the heart

Stage III

The tumor is 3 centimeters across or more. Cancer has spread to nearby lymph nodes and other body parts.

Stage IIIA Lung Cancer

Stage IIIA: One of these:

• The tumor is 3 centimeters or less. Cancer has spread to nearby lymph nodes.
• The tumor is between 3 and 5 centimeters. Cancer has spread to nearby lymph nodes and one or more of these: bronchus (airway connecting the windpipe and lung), the membranes around the lungs or the space between the lungs. Cancer partly clogs the airways.
• The tumor is between 5 and 7 centimeters. Cancer has spread to nearby lymph nodes and one or more of these: chest wall, chest lining or membranes around the heart. There are two or more tumors in the same lung.
• The tumor is 7 centimeters or more. Cancer has spread to one or more of these: the space between the lungs, the heart, large blood vessels near the heart, the windpipe, the esophagus (food pipe), the backbone or the diaphragm (the muscle between the chest and abdomen). There are two or more tumors in the same part of a lung. Cancer may have spread to nearby lymph nodes.

Stage IIIB: One of these:

• The tumor is 3 centimeters or less. Cancer has spread to nearby or distant lymph nodes.
• The tumor is between 3 and 5 centimeters. Cancer has spread to one or more of these: nearby or distant lymph nodes, a bronchus (airway connecting the windpipe and lung) or the membranes around the lungs. Cancer partly clogs airways.
• The tumor is between 5 and 7 centimeters. It has spread to nearby lymph nodes and one or more of these: the chest wall, the chest lining, the membranes around the heart, or the nerve from the backbone to the diaphragm (the muscle between the chest and abdomen). There are two or more tumors in the same lung.
• The tumor is 7 centimeters or more. Cancer has spread to nearby lymph nodes and one or more of these: the space between the lungs, the heart, large blood vessels near the heart, the windpipe, the esophagus (food pipe), the diaphragm (the muscle between the chest and abdomen) or the backbone. There are two or more tumors in the same part of a lung.

Stage IIIC: One of these:

• The tumor is between 5 and 7 centimeters. It has spread to nearby or distant lymph nodes and one or more of these: chest wall, chest lining, the nerve from the backbone to the diaphragm (the muscle between the chest and abdomen), or the membranes around the heart. There are two or more tumors in the same part of a lung.
• The tumor is 7 centimeters across or more. It has spread to nearby or distant lymph nodes and one or more of these: the space between the lungs, the heart, large blood vessels near the heart, the windpipe, the esophagus (food pipe), the diaphragm (the muscle between the chest and abdomen) or the backbone. There are two or more tumors in different parts of the same lung.

Stage IV

The tumor is any size. Cancer has spread outside the lung where the tumor formed.

Stage IVA: The tumor is any size and one or more of these:

• Cancer has spread to the other lung.
• Cancer has spread to the lining around the lungs or the heart.
• Cancer is in the fluid around the lung or heart.
• Cancer has spread outside the chest to a distant lymph node or another organ.

Stage IVB: The tumor is any size. Cancer has spread to one or more of these:

• Nearby structures
• Nearby or distant lymph nodes
• Other organs